Major world powers and Iran began two-day talks in İstanbul on Friday in an attempt to resolve an international dispute over Tehran's nuclear program, but differences between the two sides remained as deep as ever in the first day of negotiations.

The talks follow an inconclusive round of negotiations last month in Geneva. Turkey, which brokered a nuclear swap deal with Iran in a joint drive with Brazil in May, provided the venue for the talks and there was no immediate sign on Friday that its role could expand into actual involvement in the negotiations, which are taking place in İstanbul's Ottoman-era Çırağan Palace overlooking the Bosporus. The meeting, attended by 35 representatives from Iran and the P5+1 group -- consisting of the five permanent members of the UN Security Council, namely the United States, Russia, China, France, Britain, plus Germany -- were closed to the press.

Iran drew its red lines at the start of the talks on Friday and said its right to enrich uranium was not up for discussion in İstanbul.

“We will not allow any talks linked to freezing or suspending of Iran’s enrichment activities to be discussed at the meeting in İstanbul,” Massoud Zohrevand, a senior official in the Iranian delegation said. “So far this issue has not been discussed, has not been raised or mentioned by the other party,” Zohrevand said, adding, “Iran’s nuclear rights cannot be discussed.”

Western powers dismissed the May 17 nuclear swap deal brokered by Turkey and Brazil because it did not take into account the increase in Iran’s low-enriched uranium stockpile since a similar proposal was first presented to Tehran by the UN atomic agency, the International Atomic Energy Agency (IAEA), in 2009, and because the deal did not include any condition for Iran to stop its uranium enrichment activity.

Under the May 17 deal, Iran agreed to send 1,200 kilograms of its low-enriched uranium to Turkey in return for uranium enriched by Russia and France to higher levels to be used as fuel in a medical research reactor in Tehran. The US and other Western countries dismissed the deal, saying Iran’s low-enriched uranium stockpile grew to 3,000 kilograms since the IAEA offer was first made in 2009. The West also insists that Iran must stop enriching uranium, a process that would give Iran the capability to produce nuclear weapons.

Expressing Western skepticism over prospects for a breakthrough in İstanbul talks, a US State Department spokesman said in Washington on Thursday that the US merely hoped the discussions would pave the way for a process of dialogue between Iran and the international community. “We’re not expecting any big breakthroughs but we want to see a constructive process emerge that ... leads to Iran engaging with the international community in a credible process and addressing the international community’s concerns about its nuclear program,” State Department spokesman Mark Toner said.

In İstanbul, there was no statement on content of the discussions. But there were expectations ahead of the talks that, despite the disagreements between the two sides, the nuclear swap deal would be discussed in İstanbul.

Iranian officials said as they headed to the talks that they were ready to discuss reviving the swap agreement based on one brokered with Brazil and Turkey. The US did not rule out the idea either. “There would have to be some kind of updated arrangement but we’re willing to discuss that in greater detail,” Toner said when asked if such a deal would have to be revised to take into account the low-enriched uranium that Iran has produced since 2009, when the proposal was first tabled. Asked if Washington would make such a proposal, he said: “I don’t know if we’re planning to bring it up, but we’re willing to discuss it.”

Back in İstanbul, contrary to the Iranians, Western delegations attending the talks were quiet on the content of the talks. When asked to comment on what is going on behind the closed doors in Çırağan Palace, one Western official remained tightlipped, calling the Iranian statement earlier in the day a “public relations move.”

Davutoğlu in venue of the talks

Turkey, whose ties with Iran have grown closer in the recent years, says that Iran has the right to acquire nuclear energy for peaceful purposes but that it opposes nuclear weapons. Foreign Minister Ahmet Davutoğlu has said Turkey’s role in the talks would be limited to playing the host but emphasized Ankara was ready to take on a greater role should such a demand come from the parties. On Friday, Turkish diplomats confirmed that Turkey’s role was limited to hosting the negotiations. But in a sign that a Turkish involvement in later stages of the talks was still a possibility, Davutoğlu was in a different room at Çırağan Palace, having a meeting with visiting Argentine foreign minister.

On Thursday, Davutoğlu reiterated that Turkey was “against nuclear weapons, but we believe that all countries have the right to the peaceful use of nuclear energy,” at a joint news conference with his Russian counterpart, Sergei Lavrov in İstanbul. He also urged Iran to “provide assurances about its nuclear program, that there will be no intention to produce weapons,” and expressed hope that such a “good mechanism” could be achieved during the İstanbul talks. Lavrov, for his part, said the talks should look at prospects for relieving punitive sanctions on Tehran, which were imposed soon after US and other Western countries dismissed the May 17 deal. Lavrov also criticized the United States and European Union for imposing sanctions unilaterally that went beyond those agreed by the UN Security Council last June.

European Union foreign policy chief Catherine Ashton is heading the delegations representing the P5+1 group. They are meeting with Iran’s nuclear negotiator, Saeed Jalili. Nearly 400 journalists, half from outside of Turkey, were following the talks.